Brush conveyor and needling machine equipped with this conveyor

ABSTRACT

A brush conveyor, such as a velvet needling machine, has an assembly of contiguous brushes disposed in transverse rows, and a drive source for this assembly of brushes which forms a conveying plane having a predetermined direction of displacement to constitute an upper face of the conveyor. Each brush includes a body including, on its upper face, holes which are provided for receiving a tuft of hair and, on its lower face, connecting apparatus to fasten this brush to a drive source. The drive source has several parallel drive belts or chains placed between at least two drive cylinders running in the same direction. The conveyor also has a support structure for supporting the brush bodies forming the conveying plane. This support structure includes a support table having several flat support parts separated by spaces provided for the drive belts or chains. With each transverse row of brushes a connecting rail, attached to at least one brush in a row, extends along the width of the conveyor, disposed perpendicular to the direction of displacement. The connecting rail is also attached to the drive belts or chains.

BACKGROUND

The present invention relates to a brush conveyor. It also relates to aneedling machine equipped with this conveyor.

Needling machines of the prior art are equipped with a system fordriving cloths of fibers, provided with an assembly of contiguousbrushes. The two functions of these brushes are to drive the fibers andto receive these fibers when the needling takes place. They aregenerally attached to rails disposed transversely to the direction ofdrive and driven by drive belts or chains.

In systems of the prior art it is observed that the brushes have adouble rocking motion, in the vertical direction and in the horizontaldirection, while the needling is in progress and then while thestripping is in progress because of the play between the brushes and therails and the great distance between the axis of the drive chain or beltand the body of the brush. This double motion induces a marking orline-marking in the textile which is prejudicial to the quality of thefinal product. The document FR-A-2 217 460 reveals a needling machinecomprising an endless band provided with bristles which presses, under aneedling assembly, onto a horizontally mobile plate providing a supportfunction. This endless band can consist of separate links articulatedwith each other and whose function is to support the bristles. Thisconfiguration is not adapted to needling machines fitted with a conveyorcomprising an assembly of contiguous brushes and does not solve theproblem actually encountered of a double rocking motion of brushesduring needling and stripping.

SUMMARY BY THE INVENTION

The purpose of the invention is to overcome these disadvantages byproposing a brush conveyor for a velvet needling machine which makes itpossible to obtain an isotropic product without line-marking.

This purpose is achieved with a brush conveyor comprising an assembly ofcontiguous brushes disposed in transverse rows, means of driving thisassembly of brushes in order to constitute on the upper face of theconveyor a conveying plane for conveying in a predetermined direction ofdisplacement, each brush comprising a body comprising, on its upperface, holes each of which is provided for receiving a tuft of hair and,on its lower face, means of connecting this brush to the drive means,these drive means comprising several parallel drive belts or chainsplaced between at least two drive cylinders whose direction of drive iscommon and this conveyor furthermore comprising means of directlysupporting the brush bodies constituting the conveying plane.

According to the invention, the support means comprise a support tablecomprising several flat support parts separated by spaces provided forreceiving the drive belts or chains, and with each transverse row ofbrushes there is associated a connecting rail extending over the entirewidth of the conveyor, disposed perpendicular to the direction ofdisplacement and attached to the drive belts or chains.

Thus, the play of the brushes is considerably reduced during needling.Furthermore, reducing the distance between the drive means and the brushbodies contributes to reducing the harmful effects caused by the rockingof these brushes. In a conveyor according to the invention, the brushbodies are held transversely with respect to each other by means of theconnecting rails and at the same time are supported vertically by asupport table.

According to an advantageous embodiment of the invention, the conveyorfurthermore comprises means of holding the brushes constituting theconveying plane against the support table in such a way that the lowerfaces of the bodies of these brushes are held in constant contact withthe support parts, which is not at all the case in systems of the priorart.

The holding means can comprise magnetic attraction means, and the lowerfaces of the brush bodies and the support table comprise parts made offerromagnetic material.

It is also possible to make provision for the support table to compriseperforations and for the holding means to comprise means of creating avacuum through the perforations of the support table.

According to another aspect of the invention, there is proposed a velvetneedling machine comprising a brush conveyor according to one of thepreceding claims and means of needling a cloth of fibers supported anddriven by the conveyor, these needling means cooperating with thebrushes of the conveyor in order to drive fibers from the cloth into thetufts of hair of these brushes.

Other features and advantages of the invention will furthermore appearin the following description. In the accompanying drawings given asnon-limitative examples:

FIG. 1 is an exploded perspective view of a brush conveyor fitted to aneedling machine according to the invention;

FIG. 2 shows an example of assembling brushes used in a needling machineaccording to the invention;

FIG. 3 shows an example of a rail used for assembling the brushes;

FIG. 4 is a partial cross-sectional view of a transverse row of brushesillustrating a particular method of fixing a brush to a drive belt in aneedling machine according to the invention;

FIG. 5A shows a first method of holding brushes against a support table,using permanent magnets disposed in the brushes;

FIG. 5B shows a second method of holding, using permanent magnetsdisposed in the connecting rail and keys of rectangular cross-section;

FIG. 5C shows a third method of holding using magnets disposed in theconnecting rail and keys of circular cross-section; and

FIG. 6 shows a fourth method of holding the brushes against a supporttable, using a vacuum system.

DETAILED DESCRIPTION

An embodiment of a brush conveyor according to the present inventionwill now be described with reference to FIGS. 1 to 4.

A brush conveyor 1 comprises a drive device comprising, for example, twodrive cylinders 15, 16 around which are placed belts 3-6 or any otherequivalent means such as chains. The movement of these belts defines adirection of displacement D and the upper plane space existing betweenthe cylinders 15, 16 constitutes a conveying plane D whose function isto support and drive a cloth of fibers during the needling operation.This conveying plane includes an assembly 2 of brushes 120, 130, 140,150, 160, 170, 180 disposed in transverse rows 200, 201, 202,perpendicular to the direction of displacement D. When a transverse rowof brushes leaves the conveying plane P, it then describes a firstcircular trajectory around a cylinder 16, then a straight trajectorybetween the two cylinders, and another, second circular trajectoryaround the other cylinder in order finally to rejoin the conveying planeP in which the brushes are tightly contiguous in order to limit theappearance of marking defects in the needled product. When they are inthe conveying plane P, the brushes 120, 130, 140, 150, 160, 170, 180have their bodies 122, 132, 142, 152, 162, 172, 182 in direct contactwith a support table S which is substantially flat and horizontal, andthe tufts of hair 121, 131, 141, 151, 161, 171, 181, 32 (in FIG. 2)regularly implanted in receiving holes 33 on the upper faces of thebrushes form a homogeneous and isotropic assembly in which the needlespenetrate with an alternating motion.

The support table S in practice consists of several support parts 7, 8,9, 10 separated by spaces or interstices extending parallel with thedirection of displacement D and provided for receiving the drive belts3, 4, 5, 6 which in practice are flush with the support parts. Within asame transverse row 200, 201, 202, the bodies 122, 132, 142, 152, 162,172, 182 of the brushes are integrated by a connecting rail 30 (FIG. 2)which is common to all of the brushes and is itself attached to thedrive belts by attachment devices 20.

An example of connecting a row of brushes to the drive device of aconveyor according to the invention will now be described in greaterdetail with reference to FIGS. 2 to 4. The brushes 25, 26, 27 of thisconveyor each comprise a recess formed in their lower face and forming aslide, extending longitudinally in the principal axis of each brush anddesigned to receive a connecting rail 30 having, in practice, astructure of the profiled type. When a row of brushes 27, 25, 26 isformed by inserting the connecting rail 30 in the respective recesses,keys 22, 23 are then inserted, by force or otherwise, into appropriatehousings in the recesses in order to hold and integrate all of the brushbodies in a row. The brushes 25 which are above a separating spacebetween two support parts 7, 8 comprise at the level of their lower facea device 20 for attaching the brush body-connecting rail assembly to thedrive belt 3 located in the separating space in question. Thisseparating space preferably has a width substantially less than thelength of a brush so that the brushes 25 located above the separatingspace nevertheless have on their lower faces sufficient contact areaswith the support parts 7. The brushes 26 which are not located above aseparating space have their entire lower face in contact with thecorresponding support part 7.

Each attachment device 20 has a length substantially equal to the widthof a belt 3, with reference to FIGS. 2 and 4, so that it does not hinderthe movement of this belt inside the separating space. It comprises apart 43 inserted in a free space inside the connecting rail 30 andrendered integral with the latter by three transverse rods 40, 41, 42.This part 43 is designed to receive two nuts 24, 28 corresponding to twoscrews 21, 27 which clamp the belt 3 between, on the one hand, a tooth29 of the belt pierced with two holes for the passage of the screws andplaced under the belt 3 and, on the other hand, the lower face of theconnecting rail 30. This attachment device 20 thus makes it possible toattach the connecting rail 30 to the belt 3. The other brushes are alsodriven because of the mechanical connection of the brushes in a sametransverse row which is procured by the presence of the connecting rail.With this attachment method, the lower faces of the brush bodies 27, 25,26 can be in direct contact with the support parts 7, 8, whichcontributes to a substantial improvement in the stability of thesebrushes during needling.

The rocking effects of the brushes can furthermore be considerablyreduced by using an active holding of the brush bodies against thesupport table, as shown in FIGS. 5A, 5B, 5C and 6.

A first embodiment of this holding consists in using the well knowneffects of magnetic attraction. It is possible, for example, withreference to FIG. 5A, to provide on the lower face of the body 51 ofeach brush rendered integral with a connecting rail 30 by keys 57/1,57/2, permanent magnets 52, 53 made of ferrite or rare earth materialssuch as Samarium-Cobalt or Iron-Neodymium-Boron and to use a supporttable 55 made of a ferromagnetic material. The magnetic attractioneffects between the magnets and the ferromagnetic table will generateattraction forces in a direction substantially normal to the plane ofthe support table. It is also possible to make provisions for placingpermanent magnets on the support table, for example in the form of tapesor strips or in any other form, and to make the brush bodies from aferromagnetic material.

In a second embodiment shown in FIG. 5B, permanent magnets 56 aredisposed in the internal space 50 of the connecting rail 30, the supporttable 55 still being made of a ferromagnetic material.

In a third embodiment shown in FIG. 5C, magnets 56 are also disposedinside the connecting rail 59, the latter and the brush bodies beingdesigned to receive keys 58/1, 58/2 having a circular cross-section.This embodiment has the advantage of an automatic taking up of lateralplay.

A fourth embodiment of active holding of the brushes against the supporttable consists in using attraction by vacuum, as shown in FIG. 6. Avacuum generating device 67 comprises suction equipment 68 disposedunder a support table 65 provided with perforations 66. A vacuum is thuscreated at the surface of the support table 65. This vacuum must beadjusted to ensure a correct holding of the brush bodies 61 duringneedling operations.

In each of the embodiments mentioned above, the holding means 52, 53; 67cooperate with the connecting means 50; 60 to provide the greateststability to the brush bodies when they are simultaneously subjected tothe driving forces transmitted by the belts and by the connecting railsand to the alternating needling forces. It is also possible to combineseveral separate techniques for holding the brushes against the supporttable.

The brush conveyor 1 which has just been described can be usedadvantageously in a velvet needling machine but it can also be used inother industrial equipment requiring a conveying surface having abrush-like surface state.

The invention is not of course limited to the example embodiments whichhave just been described and numerous modifications can be applied tothese examples without departing from the scope of the invention. Thusit is possible to have numerous other arrangements for the embodiment ofthe holding means. In particular, the optimum arrangement of thepermanent magnets can be determined according to electromagneticcalculations. Furthermore, it is possible to provide multiple variantsfor the method of attaching the brush bodies to the drive belts orchains. Furthermore, the shape of the brushes, the density of the hairs,the arrangement of the brushes in the conveying plane and their methodof assembly do not constitute limitations to the scope of the presentinvention.

We claim:
 1. A brush conveyor, comprising: an assembly of contiguousbrushes disposed in transverse rows, means of driving this assembly ofbrushes in order to constitute on an upper face of the conveyor aconveying plane having a predetermined direction of displacement, eachbrush comprising a body comprising, on its upper face, holes each ofwhich is provided for receiving a tuft of hair and, on its lower face,means for connecting this brush to drive means, said drive meanscomprising several parallel drive belts or chains placed between atleast two drive cylinders whose direction of drive is common, and saidconveyor furthermore comprising means for directly supporting the brushbodies constituting the conveying plane, said support means comprise asupport table comprising several flat support parts separated by spacesprovided for receiving the drive belts or chains, and in that with eachtransverse row of brushes there is a connecting rail attached to atleast one of said brushes in said row, said connecting rail extendingalong the width of the conveyor, disposed perpendicular to the directionof displacement and attached to the drive belts or chains.
 2. The brushconveyor according to claim 1, characterized in that each brush bodycomprises, as a means of connection, a recess over its entire lengthprovided for receiving the connecting rail and means for locking theconnection, this recess and this connecting rail being designed toensure direct contact of lower faces of the bodies on the support parts.3. The brush conveyor according to claim 2, characterized in that theconnection means furthermore comprise, for each rail, means forattaching said rail to each drive belt or chain, said means beingpartially engaged in the recesses of the bodies of the brushes locatedabove each belt or chain.
 4. The brush conveyor according to claim 2,characterized in that the connecting rails associated with eachtransverse row of brushes have a structure including a cross sectionhaving a generally main C-channel shape having a pair of depending legs,each said leg defining a keyway.
 5. The brush conveyor according toclaim 2, characterized in that it furthermore comprises means forholding the brushes constituting the conveying plane against the supporttable in such a way that the lower faces of the bodies of said brushesare held in constant contact with the support parts.
 6. The brushconveyor according to claim 5, characterized in that the holding meanscomprise magnetic attraction means and in that the lower faces of thebodies of the brushes and the support table comprise parts made offerromagnetic material.
 7. The brush conveyor according to claim 6,characterized in that the magnetic attraction means comprise permanentmagnets.
 8. The brush conveyor according to claim 7, characterized inthat the permanent magnets are located on the lower faces of the bodiesof the brushes.
 9. The brush conveyor according to claim 7,characterized in that the permanent magnets are located on the supporttable.
 10. The brush conveyor according to claim 7, characterized inthat the permanent magnets are disposed on the connecting rail.
 11. Thebrush conveyor according to claim 5, characterized in that the supporttable comprises perforations and in that the holding means comprisemeans for creating a vacuum through the perforations of the supporttable.
 12. The brush conveyor according to claim 5, characterized inthat the connection locking means comprise keys of substantiallyrectangular cross-section, and in that the connecting rail and the brushbodies are configured to receive said keys.
 13. The brush conveyoraccording to claim 5, characterized in that the connection locking meanscomprise keys of substantially circular cross-section, and in that theconnecting rail and the brush bodies are configured to receive saidkeys.
 14. A velvet needling machine comprising a brush conveyor ofcontiguous brushes disposed in transverse rows, means of driving thisassembly of brushes in order to constitute on an upper face of theconveyor a conveying plane having a predetermined direction ofdisplacement, each brush comprising a body comprising, on its upperface, holes each of which is provided for receiving a tuft of hair and,on its lower face, means for connecting this brush to drive means, saiddrive means comprising several parallel drive belts or chains between atleast two drive cylinders whose direction of drive is common, and saidconveyor furthermore comprising means for directly supporting the brushbodies constituting the conveying plane, these support means comprise asupport table comprising several flat support parts separated by spacesprovided for receiving the drive belts or chains, and in that with eachtransverse row of brushes there is a connecting rail attached to atleast one of said brushes, the connecting rail extending along the widthof the conveyor, disposed perpendicular to the direction of displacementand attached to the drive belts or chains, means for needling a cloth offibers supported and driven by the conveyor, said needling meanscooperating with the brushes of the conveyor in order to drive fibersfrom the cloth into the tufts of hair of said brushes.
 15. The brushconveyor according to claim 1, characterized in that each saidconnecting rail extends over the entire width of the conveyor.
 16. Thebrush conveyor according to claim 3, characterized in that itfurthermore comprises means for holding the brushes constituting theconveying plane against the support table in such a way that the lowerfaces of the bodies of said brushes are held in constant contact withthe support parts.
 17. The brush conveyor according to claim 4,characterized in that it furthermore comprises means for holding thebrushes constituting the conveying plane against the support table insuch a way that the lower faces of the bodies of said brushes are heldin constant contact with the support parts.